Introduction

You are developing a REST back end of an address book app. You were asked to implement endpoints to fetch a list of contacts (with phase matching and results limiting) and to fetch details of a single contact and to delete a given contact.

As the database is not ready, you are provided with a fake database layer exported with ./src/database/fakeDatabase.js.

App requirements

Your implementation has to:

• make all tests pass,
• modify helper functions if needed,
• fulfil the requirements of HTTP endpoints described below:

GET /contacts

• The response HTTP status should be: 200 OK.
• The response Content-Type header should be: application/json.
• The response body should be: a JSON array with details of all contacts as loaded from the database (each contact has an ID, a name, a phone and an array of strings addressLines).
• The contacts in the response body are sorted by their name, which means a contact with the name of Abbigail Wunsch would be first and a contact with the name of Zoila Daugherty II would be last.
• If the phrase URL query parameter is present:
  • in the response body, filter out contacts with names not matching phrase;
  • the phrase and the contact's name are compared lowercase, which means that both Theresa Gorczany and Zakary Mayer match the following phrase=zA;
  • If there are no contacts matching the phrase, then the response body contains only an empty JSON array as there are no contacts to include in it.
  • If the phrase is empty (phrase=), then the response has the 400 Bad Request HTTP status and an empty response body.
• If the limit URL query parameter is present:
  • the number of the returned contacts should be limited by the limit number;
    • e.g., if there are 3 contacts matching the phrase parameter and the limit is 10, then those 3 contacts are included in the response body;
    • e.g., if there are 10 contacts matching the phrase parameter and the limit is 3, then only the first 3 contacts (sorted by name) are included.
  • If the limit is not a valid non-negative integer (0, 1, 2 and so on), then the response has the 400 Bad Request HTTP status and an empty response body.

GET /contacts/

• If a contact with ID value <contact-id> exists:
  • the response HTTP status should be: 200 OK;
  • the response Content-Type header should be: application/json;
  • the response body should be: a JSON object with details of that contact loaded from the database (ID, name, phone and an array of strings addressLines).
• If a contact with ID value <contact-id> does not exist:
  • the response HTTP status should be: 404 Not Found.

DELETE /contacts/

• If a contact with ID value <contact-id> exists:
  • the response HTTP status should be: 204 No Content;
  • that contact is deleted, which means it is no longer included in the response to GET /contacts requests and its details are no longer available when making the GET /contacts/<contact-id> request.
• If a contact with ID value <contact-id> does not exist:
  • the response HTTP status should be: 404 Not Found.

GET /ping (has already been implemented)

• The response HTTP status should be: 200 OK.
• The response Content-Type header should be: text/plain.
• The response body should be: pong.

For all requests

• The request to the URL path different than the expected ones would get the 404 Not Found HTTP status.
• The request to the supported URL path, but with an unexpected HTTP method would get the 405 Method Not Allowed HTTP status.

Setup

This app was originally created with Node.js 12.13.1 / npm 6.12.1. You can use nvm to make sure you are working with the same version of Node.js. Run nvm install and nvm will set up Node.js based on the .nvmrc file.

Follow these steps to set up the app:

1. npm install – install dependencies.
2. npm test – run all tests (should fail unless you implement the task).
3. npm start – serve the app at http://localhost:8080/ (you can check if it works by opening the http://localhost:8080/ping in your browser or executing the curl http://localhost:8080/ping in your terminal – pong should be printed).

There is also the npm run test:watch command available to start the test runner in the watch mode. It runs tests related to modified files only.

You can also use the npm run start:watch command to serve the app in the watch mode. It restarts the server every time the code is modified.